Parasitic Power Losses in Turbine Bearings©

Test results indicate that 25–50 percent of total fluid film bearing losses in turbomachinery are consumed in simply feeding oil to the bearings. The two major components of these losses are evaluated in this paper: 1) through-flow losses absorbed by the oil in its passage to and from the actual load-carrying bearing elements, and 2) surface frictional drag by the oil as it contacts rotating surfaces at bearing oil feed grooves and other exposed zones. Relations are developed for estimating these parasitic losses for both fixed-element and tilting-pad journal and thrust bearings.